If we look away from Tuscany to our own England, however, we shall find on many a deserted down or lonely tor ample evidence of the causes which led the people of this ancient Etruscan town to build their citadel at so great a height above the neighbouring valley. Fiesole, says Dante, in a well-known verse, was the mother of Florence. Even so in England, Old Sarum was indeed the mother of Salisbury, and Caer Badon or Sulis was the mother of Bath. And when there was first a Faesulae on the hill here there could be no Florence, as when first there was an Old Sarum on the Wiltshire downs there could be no Salisbury, and when first there was a Caer Badon on the heights of Avon there could be no Bath. In very early times indeed, in the European land area, when men began first to gather together into towns or villages, two necessities determined their choice of a place to dwell in: first, food-supply (including water); and second, defence. Hence every early community stands, to start with, near its own cultivable territory, usually a broad river-valley, an alluvial plain, a 'carse' or lowland, for uplands as yet were incapable of tillage by the primitive agriculture of those early epochs. But it does not stand actually _in_ the carse; it occupies as a rule the nearest convenient height or hill-top, most often the one that juts out farthest into the subjacent plain, by way of security against the attack of enemies. This is the beginning of almost every great historical European town; it is an arx or acropolis overhanging its own tilth or _ager_; and though in many cases the town came down at last into the valley, retaining still its old name, yet the remains of the old earthworks or walls on the hill-top above often bear witness to our own day to the original site of the antique settlement upon the high places.